Field of the Invention
The present invention relates to a method for preventing seam ravel of multi-thread chain stitches in which multi-thread chain stitch seams are formed with a needle thread and a looper thread by using a multi-thread chain stitching sewing machine, typically represented by a horizontal tube type one, and it is configured to prevent seam ravel from occurring at an end portion of the multi-thread chain stitch seams. The present invention also relates to a seam ravel preventing apparatus for a multi-thread chain stitch sewing machine, and a multi-thread chain stitch seam structure.
Description of the Prior Art
Background Art
A multi-thread chain stitch sewing machine of general horizontal tube type or the like includes a needle moving up and down while holding a needle thread, and a looper which moves forward and backward while holding a looper thread in a direction substantially orthogonal to a vertical movement path of the needle. The multi-thread chain stitch sewing machine forms multi-thread chain stitch seams on a fabric by repeating the step in which a needle thread loop formed below a needle plate by the needle is caught by the forward movement action of the looper, and the step in which the needle thread is interloped with the looper thread held by the looper.